Optical technologies can play a strategic role in improving the performance, functionality, and reducing the mass of various spacecraft technologies, such as true time-delay T/R modules for phased-array antennas and optical sensor systems for satellite navigation and systems status. However, current photonic and fiber-optic systems tend to be bulky relative to the requirements for space applications. Micro integrated-optic circuits increase the integration of optical components on a single substrate, to provide multi-function optical processing and switching similar to electronic integrated circuits. This minimizes the number of external optical interconnections required and sensitivity to external vibrations; maximizing the system information capacity, optical throughput, and reliability, while minimizing the overall system size and weight. This paper considers a systematic development of MEMS integrated-optic circuits on SOI for various space application. A unique blend of MEMS, smart-material and photonic technologies is employed to miniaturize the size of the basic components, while improving on the attainable performance.